41.
Stochastic Processes
- Parzen, Emanuel
42.
EVALUATION OF UNCERTAINTIES AND ITS INFLUENCE IN THE ANALYSIS OF WELLBORE STABILITY
- BRUNO BROESIGKE HOLZBERG
The study on wellbore stability has as one of its main application the determination of the safe range of the drilling-fluid density. The wellbore stability analysis is controlled by a number of parameters that generally present uncertainties associated to their values. In conventional methods, these uncertainties are not considered. The purpose of this work is to develop methodologies of analysis of wellbore stability that consider the uncertainties associated to the controlling parameters.Methods for quantifying the uncertainties associated to the parameters are presented for the case of an open well and for the case of new well located on a development...
43.
APPLICATION OF PROBABILISTIC AND STATISTIC TECHNIQUES IN THE EVALUATION OF THE ADEQUACY OF IN SITU EXPERIMENTAL RESULTS
- GERSON JACQUES MIRANDA DOS ANJOS
It is well known that there is an inherent variability in the values of undrained shear strength of soil collected at different depths. In the case of natural deposits, this variability is attributed to the randomness associated with the geological processes involved in the formation of the deposits.The study on spatial variability of soil properties like undrained shear strength (Su), cone bearing (qc) and pore pressure(delta u), is the main goal of this thesis. Probabilistic and Statistical approaches have been applied to analyze results of cone penetration tests performed in quartenary soft clay deposits located in the Baixada Santista Sao...
44.
ESTATISTICAL METHODS FOR RESERVE ESTIMATION
- JESSICA QUINTANILHA KUBRUSLY
The CNSP number 18 bylaw promulgated on August 25, 1998 obliging paymenthas become mandatory when even not communicated, IBNR. Hence, estimatesfrom IBNR have become routine in all brazilian insurance companies. Someways to determine these compensations shall be clarified in this report. Inaddition, I shall try to outline a new formula to estimate the IBNR Thedifferent paths to reach the very same estimate can be compared with thepurpose of underlying the pro's and the con's of each estimate.
45.
Simulação de campos aleatorios markovianos : uma introdução voltada a modelagem estocastica de reservatorios de petroleo
- Paulo Carlos Saldanha Filho
A simulação estocástica tem sido utilizada na caracterização de reservatórios de petróleo como ferramenta de modelagem capaz de conciliar informações de fontes diversas. Ao mesmo tempo, preserva a variabilidade do fenômeno modelado e permite a transferência do conhecimento geológico para modelos numéricos de fluxo, cujas previsões sobre o comportamento do reservatório servirão de base às decisões gerenciais quanto ao manejo de recursos. Diversos modelos estocásticos têm sido utilizados e/ou sugeridos, em função da natureza do fenômeno a ser descrito. Os Campos Aleatórios Markovianos (CAMs) surgem como alternativa para modelagem de variáveis discretas, em reservatórios com arquitetura de fácies em mosaico....
46.
Modelos bayesianos no paramétricos de fiabilidad en ensayos de vida acelerados
- Maté Jiménez, Carlos
La memoria consta de cuatro capítulos. En el capitulo 0 se describen los elementos básicos de los problemas a estudiar. En el capitulo 1 se introduce el modelo de ensayos de vida acelerada bayesiano no paramétrico, que el autor denomina alt-bn. En este capitulo se dan procedimientos para la estimación de la función de distribución de la variable en estudio. En el capitulo 2 se extienden los resultados del capitulo 1 al caso de funciones de aceleración generales. En el capitulo 3 se extienden los resultados anteriores al caso de datos censurados aleatoriamente por la derecha. Se proporcionan estimadores de...
47.
Triangle functions and composition of probability distribution functions.
- Alsina Catalá, Claudi
The equations of left and right distributivity of composition of distribution functions over triangle functions are solved in a restricted domain.
48.
A note on the Polya-Eggenberger distributions with s=1 and some applications
- Guenther, William C.
Although cumulative probabilities for the Pólya-Eggenberger distributions can be easily found in modern computing facilities, the special cases s=1 can be handled with hypergeometric tables. Applications are mentioned
49.
Propiedades de las funciones de medias de las distribuciones truncadas
- Ruiz Gómez, José María; Zoroa Terol, Procopio
In this paper, by using the concept of truncated distributions obtained from a unidimensional distribution of a given distribution function F(x), the concept of function of means m(x) is introduced and its properties studied. Necessary conditions for a given real function to be a function of means are obtained. The conjecture that the given conditions are also sufficient and the problem of an explicit formulation for the inverse of the functional transformation studied are also stated
50.
Comment on "On some statistical paradoxes and non-conglomerability" by Bruce Hill
- Levi, Isaac
Those who follow Harold Jeffreys in using improper priors together with likelihoods to determine posteriors have thought of the improper measures as probability measures of a deviant sort. This is a mistake. Probability measures are finite measures. Improper distributions generate s-finite measures
51.
Distribuciones continuas truncadas y sus funciones de medias
- Ruiz Gómez, José María; Zoroa Terol, Procopio
In a previous paper [6], the functions of means in general distributions were studied. In this paper we deal only with distributions of the continuous type, the characterization of their functions of means is obtained and the problem of inversion of the functional transformation under study is completely solved
52.
On Tchebycheff's type inequalities
- Ferentinos, Kosmas
Three inequalities of Tchebycheff type are presented. Two of them give lower bounds for the probability of intervals not necessarily symmetric around the mean. The third one generalizes the extension of Tchebycheff's inequalities given by Miyamoto (1978). They are based on the inequality of Markov. Attainability of lower bounds is also discussed
53.
Probability of reversal in an election with more than two candidates
- Rohatgi, Vijay K.
Consider an election with three candidates A1, A2 and A3. Suppose that N is the total number of votes cast of which A1 receives a1 votes, A2 receives a2 votes and A3 receives a3 = N - (a1 + a2) votes. We assume without loss of generality that a1 > a2 > a3. Suppose further that n votes are irregular or suspect. If these votes are removed it is possible that the result of the election may be reversed. Does such a possibility preclude the determination of the rightful winner without holding a new election?
54.
Económica
- Mentz, Raúl P.
55.
Aproximación aleatoria de cuerpos convexos
- Affentranger, Fernando
Problems related to the random approximation of convex bodies fall into the field of integral geometry and geometric probabilities. The aim of this paper is to give a survey of known results about the stochastic model that has received special attention in the literature and that can be described as follows:
Let K be a d-dimensional convex body in Eucliden space Rd, d = 2. Denote by Hn the convex hull of n independent random points X1, ..., Xn distributed identically and uniformly in the interior of K. If f is a random variable on d-dimensional polytopes on Rd, we define...
56.
Sesgo de la disponibilidad en estudiantes universitarios
- Salcedo, Audy; Mosquera, Julio
The objective of this paper is to report an investigation about the availability bias in university students. Availability Bias, or Availability Heuristics, refers to the process in which people estimate the possibility of occurrence of an event based on their experience related to a certain case of that event. For this research an intentional sample of 22 1 students was selected. The data was recollected through a written survey. In the first phase, a case (taken from Tversky and Kahneman, 1974) was
presented to the participants, who had to choose one of three given options. In the second phase, students had...
57.
Discursos leídos ante la Real Academia de Ciencias Exactas, Físicas y Naturales, en la recepción pública del Señor Don Miguel Merino [Texto impreso]
- Merino Melchor, Miguel
58.
Discurso leído en la Universidad Central por el Licenciado D. Ambrosio Moya de la Torre, catedrático de matemáticas de dicha Universidad, en el acto de recibir la investidura de Doctor en ciencias físico-matemáticas [Texto impreso]
- Moya de la Torre, Ambrosio
59.
Apuntes hechos por el profesor Don Antonio Portuondo [Texto impreso] : curso de 1898 a 99
- Portuondo y Barceló, Antonio
Precede al título: Escuela Especial de Ingenieros de Caminos, Canales y Puertos
60.
Inferência sobre os hiperparâmetros dos modelos estruturais usando Bootstrap
- Juliana Aparecida Ribeiro
This dissertation is based on the decomposition of times series via non-observed components, through structural models. An alternative way to rewrite the structural models is by using the state space form. Once this transcription is done, the Kalman filter is used for updating the state vector and constructing the likelihood function to estimate the hyperparameters of the model. The bootstrap resampling technique is applied to make inferences on the hyperparameters of the models, attending for the construction of confidence intervals, which is made in the programming language Ox. The results of the simulations and a real time series application verify...
